The present invention relates to shroud assemblies used in gas turbine engines, and more particularly to a seal for filling a cavity formed between a turbine nozzle hanger and a surrounding frame.
In a gas turbine engine, hot gas exits a combustor and is utilized by a turbine for conversion to mechanical energy. This mechanical energy drives an upstream high pressure compressor. The turbine comprises a plurality of blades which are carried by a turbine rotor. The tips of the rotor blades are tightly circumscribed by a plurality of shroud segments. The shrouds are supported by a plurality of shroud supports or “hangers” which are located radially outward from the shrouds. The shrouds and hangers must be segmented circumferentially to accommodate differential thermal expansion rates and to maintain blade tip clearance control.
Each shroud connects to a hanger in such a manner that a plenum region is defined therebetween. In operation this plenum region receives a flow of coolant, such as air extracted (bled) from the compressor. Any leakage of cooling air between the numerous components of the shroud assembly increases the total amount of bleed air required, reducing engine efficiency.
Accordingly, there is a need for a shroud assembly with improved sealing.